Method and system for validating a position of a microphone

ABSTRACT

A method comprising: receiving a reference time delay between a first reference signal emitted by a first speaker and a second reference signal emitted by a second speaker, each recorded by a microphone having a target position; using the microphone positioned at an actual position, recording a first sound signal emitted by the first speaker and a second sound signal emitted by the second speaker; determining an actual time delay between the first and second sound signals; comparing the actual time delay to the reference time delay; determining a match or a mismatch between the actual position and the target position for the given microphone; and outputting an indication of the match/mismatch.

TECHNICAL FIELD

The present invention relates to the field of methods and system fordetermining the position of a microphone, and more particularly tomethods and systems for determining the position of a microphone usingsound signals generated by speakers.

BACKGROUND

In the context of simulators such as vehicle simulators, the location ofa microphone to be used for sound tests or calibration is usuallyimportant to ensure repeatability such as when running soundQualification Test Guide (QTG) tests. If when running sound tests themicrophone is positioned at a location different from previouspositions, there will be difference in travel distance between thespeakers and the microphone and this difference in travel distance maycause a dephasing of the period signals which will cause differentinterference and modify the recorded signal amplitudes.

Usually, pictures are provided to help a user installing the microphoneat the desired position. However, this solution for installing themicrophone at the desired position may not be adequate since it issubject to individual interpretation of the pictures.

Another solution consists in providing the user with a custom fixedtripod on which the microphone is installed. However, such a customfixed tripod may be obstructive and the installation of the custom fixedtripod can be time consuming in addition to be expensive.

Therefore, there is a need for an improved method and system fordetermining whether a microphone is positioned at a desired position.

SUMMARY

According to a first broad aspect, there is provided acomputer-implemented method for determining whether a given microphoneoccupies a target position, comprising: receiving a reference time delaybetween a first reference signal emitted by a first speaker and recordedby a reference microphone having the target position and a secondreference signal emitted by a second speaker and recorded by thereference microphone having the target position, the first and secondspeakers each having a fixed position and the emission of the first andsecond reference signals being spaced apart by a reference time delay;using the given microphone positioned at a given position, recording afirst sound signal emitted by the first speaker and a second soundsignal emitted by the second speaker, the emission of the first andsecond sound signals being spaced apart by the reference time delay;determining an actual time delay between the first sound signal and thesecond sound signal; comparing the actual time delay to the referencetime delay; determining a match between the given position and thetarget position for the given microphone if the actual time delaycorresponds to the reference time delay and a mismatch between the givenposition and the target position for the given microphone if the actualtime delay is different from the reference time delay; and outputting anindication of one of the match and the mismatch.

In one embodiment, the reference time delay is chosen to be greater thana reverberation time.

In one embodiment, said outputting an indication comprises outputting anindication of the match between the given position and the targetposition for the given microphone.

In one embodiment, said outputting an indication comprises outputting anindication of the mismatch between the given position and the targetposition for the given microphone.

In one embodiment, the indication of the mismatch comprises a suggesteddisplacement for displacing the given microphone.

In one embodiment, said outputting an indication comprises outputtingone of a visual indication and an audio indication.

In one embodiment, the method further comprises: emitting the firstsound signal via the first speaker; and emitting the second sound signalvia the second speaker after the reference time delay.

In one embodiment, said determining the match comprises determining thematch between the given position and the target position for the givenmicrophone if the actual time delay is comprised within a range of timedelay containing the reference time delay and said determining themismatch comprises determining the mismatch between the given positionand the target position for the given microphone if the actual timedelay is outside of the range of time delay.

In one embodiment, the method further comprises: receiving a furtherreference delay between the second reference signal and a thirdreference signal emitted by a third speaker and recorded by themicrophone having the target position, the third speaker having a fixedlocation and the emission of the second and third reference signalsbeing spaced apart by a predefined time delay; recording, via the givenmicrophone positioned at the given position, a third sound signalemitted by the third speaker, the emission of the second and third soundsignals being spaced apart by the predefined time delay; determining agiven time delay between the second sound signal and the third soundsignal; and comparing the given time delay to the further referencedelay; said determining the match comprising determining the matchbetween the given position and the target position for the givenmicrophone if the actual time delay corresponds to the reference timedelay and the given time delay corresponds to the further referencedelay, and said determining the mismatch comprising determining themismatch between the given position and the target position for thegiven microphone if at least one of the actual time delay is differentfrom the reference time delay and the given time delay is different fromthe further reference delay.

In one embodiment, the predefined time delay is chosen to be greaterthan a reverberation time.

In one embodiment, said determining the match comprises determining thematch between the given position and the target position for the givenmicrophone if the actual time delay is comprised within a first range oftime delay containing the reference time delay and the given time delayis comprised within a second range of time delay containing the furtherreference delay, and said determining the mismatch comprises determiningthe mismatch between the given position and the target position for thegiven microphone if at least one of the actual time delay is outside thefirst range of time delay and the given time delay is outside the secondrange of time delay.

In one embodiment, the reference microphone corresponds to the givenmicrophone.

According to a second broad aspect, there is provided a system fordetermining whether a given microphone occupies a target position,comprising: a communication unit for at least one of receiving andtransmitting data, a memory and a processing unit configured forexecuting the steps of the above method.

According to a third broad aspect, there is provided a system fordetermining whether a given microphone occupies a target position,comprising: a sound recording unit connectable to the given microphoneto be positioned at a given position, the sound recording unitconfigured for recording a first sound signal emitted by a first speakerand a second sound signal emitted by a second speaker, the emission ofthe first and second sound signals being spaced apart by a referencetime delay, the first and second speakers each having a fixed position;a time delay unit configured for determining an actual time delaybetween the first sound signal and the second sound signal; a matchidentification unit configured for: receiving a reference time delaybetween a first reference signal emitted by the first speaker andrecorded by a reference microphone having a target position and a secondreference signal emitted by the second speaker and recorded by thereference microphone having the reference position, the emission of thefirst and second reference signals being spaced apart by the referencetime delay; comparing the actual time delay to the reference time delay;determining a match between the given position and the referenceposition for the given microphone if the actual time delay correspondsto the reference time delay and a mismatch between the given positionand the target position for the given microphone if the actual timedelay is different from the reference time delay; and outputting anindication of one of the match and the mismatch.

In one embodiment, the reference time delay is chosen to be greater thana reverberation time.

In one embodiment, the match identification unit is configured foroutputting the indication of the match between the given position andthe target position for the given microphone.

In one embodiment, the match identification unit is configured foroutputting the indication of the mismatch between the given position andthe target position for the given microphone.

In one embodiment, the indication of the mismatch comprises a suggesteddisplacement for displacing the given microphone.

In one embodiment, the match identification unit is configured foroutputting one of a visual indication and an audio indication.

In one embodiment, the system further comprises a sound emitting unitconfigured for: emitting the first sound signal via the first speaker;and emitting the second sound signal via the second speaker after thereference time delay.

In one embodiment, the match identification unit is configured for:determining the match between the given position and the target positionfor the given microphone if the actual time delay is comprised within arange of time delay containing the reference time delay; and determiningthe mismatch between the given position and the target position for thegiven microphone if the actual time delay is outside of the range oftime delay.

In one embodiment, the sound recording unit is further configured forrecording, via the given microphone positioned at the given position, athird sound signal emitted by a third speaker, the emission of thesecond and third sound signals being spaced apart by a predefined timedelay; the time delay unit is further configured for determining a giventime delay between the second sound signal and the third sound signal;and the match identification unit is further configured for: receiving afurther reference delay between the second reference signal and a thirdreference signal emitted by the third speaker and recorded by themicrophone having the target position, the third speaker having a fixedlocation and the emission of the second and third reference signalsbeing spaced apart by the predefined time delay; comparing the giventime delay to the further reference delay; determining the match betweenthe given position and the reference position for the given microphoneif the actual time delay corresponds to the reference time delay and thegiven time delay corresponds to the further reference delay, anddetermining the mismatch between the given position and the referenceposition for the given microphone if at least one of the actual timedelay is different from the reference time delay and the given timedelay is different from the further reference delay.

In one embodiment, the predefined time delay is chosen to be greaterthan a reverberation time.

In one embodiment, the match identification unit is configured for:determining the match between the given position and the target positionfor the given microphone if the actual time delay is comprised within afirst range of time delay containing the reference time delay and thegiven time delay is comprised within a second range of time delaycontaining the further reference delay; and determining the mismatchbetween the given position and the target position for the givenmicrophone if at least one of the actual time delay is outside the firstrange of time delay and the given time delay is outside the second rangeof time delay.

In one embodiment, the reference microphone corresponds to the givenmicrophone.

According to another broad aspect, there is provided acomputer-implemented method for determining whether a microphoneoccupies a desired position, comprising: receiving a target position forthe microphone; sequentially emitting a first sound signal via a firstspeaker positioned at a first speaker position, and a second soundsignal via a second speaker positioned at a second speaker position;measuring a first elapsed time between the emission of the first soundsignal by the first speaker and a detection of the first sound signal bythe microphone, and a second elapsed time between the emission of thesecond sound signal by the second speaker and a detection of the secondsound signal by the microphone; determining a first distance between thefirst speaker position and the microphone using the first elapsed time,and a second distance between the second speaker position and themicrophone using the second elapsed time and; determining an actualposition of the microphone using the first and second distances and thefirst and second speaker positions; comparing the actual position of themicrophone to the target position; determining a match between theactual position and the target position for the microphone if the actualposition corresponds to the target position and a mismatch between theactual position and the target position for the given microphone if theactual position is different from the target position; and outputting anindication of one of the match and the mismatch.

In one embodiment, the method further comprises: emitting a third soundsignal via a third speaker positioned at a third speaker position;measuring a third elapsed time between the emission of the third soundsignal by the third speaker and a detection of the third sound signal bythe microphone; and determining a third distance between the thirdspeaker position and the microphone using the third elapsed time, saiddetermining the actual position of the microphone is performed usingfurther the third distance and the third speaker position.

In one embodiment, the method further comprises recording, via themicrophone, the first sound signal emitted by the first speaker, thesecond sound signal emitted by the second speaker and the third soundsignal emitted by the third speaker.

In one embodiment, an emission of the first sound signal and an emissionof the second sound signal are spaced apart by a first time delay and anemission of the second sound signal and an emission of the third soundsignal are spaced apart by a second time delay.

In one embodiment, the first and second time delays are each greaterthan a reverberation time.

In one embodiment, said outputting the indication comprises outputtingthe indication of the match between the actual position and the targetposition for the microphone.

In one embodiment, said outputting the indication comprises outputtingthe indication of the mismatch between the actual position and thetarget position for the given microphone.

In one embodiment, the method further comprises determining a suggesteddisplacement for the microphone using the actual position and the targetposition, said outputting the indication of the mismatch comprisingoutputting the suggested displacement for the microphone.

In one embodiment, said outputting an indication comprises outputtingone of a visual indication and an audio indication.

In one embodiment, said determining the match comprises determining thematch between the actual position and the target position for the givenmicrophone if the actual position is comprised within a range ofposition containing the target position and said determining themismatch comprises determining the mismatch between the actual positionand the target position for the given microphone if the actual positionis outside of the range of position.

In one embodiment, said determining an actual position of the microphoneis performed using a trilateration method.

In one embodiment, said determining an actual position of the microphoneis performed using a nonlinear least squares fitting method.

According to a further broad aspect, there is provided a system fordetermining whether a microphone occupies a target position, comprising:a communication unit for at least one of receiving and transmittingdata, a memory and a processing unit configured for executing the stepsof the above method.

According to still another broad aspect, there is provided a system fordetermining whether a microphone occupies a desired position,comprising: a sound emitting unit configured for successively emitting afirst sound signal via a first speaker positioned at a first speakerposition and a second sound signal via a second speaker positioned at asecond speaker position; a distance measurement unit configured for:measuring a first elapsed time between the emission of the first soundsignal by the first speaker and a detection of the first sound signal bythe microphone and a second elapsed time between the emission of thesecond sound signal by the second speaker and a detection of the secondsound signal by the microphone; and determining a first distance betweenthe first speaker position and the microphone using the first elapsedtime and a second distance between the second speaker position and themicrophone using the second elapsed time and; a position determiningunit configured for determining an actual position of the microphoneusing the first and second distances and the first and second speakerpositions; a match identification unit configured for: receiving atarget position for the microphone; comparing the actual position of themicrophone to the target position; determining a match between theactual position and the target position for the microphone if the actualposition corresponds to the target position and a mismatch between theactual position and the target position for the given microphone if theactual position is different from the target position; and outputting anindication of one of the match and the mismatch.

In one embodiment, the sound emitting unit is further configured foremitting a third sound signal via a third speaker positioned at a thirdspeaker position; the distance measurement unit is further configuredfor: measuring a third elapsed time between the emission of the thirdsound signal by the third speaker and a detection of the third soundsignal by the microphone; and determining a third distance between thethird speaker position and the microphone using the third elapsed time;and the position determining unit is configured for determining theactual position of the microphone using further the third distance andthe third speaker position.

In one embodiment, the system further comprises a sound recording unitconnectable to the microphone and configured for recording, via themicrophone, the first sound signal emitted by the first speaker, thesecond sound signal emitted by the second speaker and the third soundsignal emitted by the third speaker.

In one embodiment, an emission of the first sound signal and an emissionof the second sound signal are spaced apart by a first time delay and anemission of the second sound signal and an emission of the third soundsignal are spaced apart by a second time delay.

In one embodiment, the first and second time delays are each greaterthan a reverberation time.

In one embodiment, the match identification unit is configured foroutputting the indication of the match between the actual position andthe target position for the microphone.

In one embodiment, the match identification unit is configured foroutputting the indication of the mismatch between the actual positionand the target position for the given microphone.

In one embodiment, the system further comprises a displacementdetermining unit configured for determining a suggested displacement forthe microphone using the actual position and the target position, thematch identification unit being configured for outputting the suggesteddisplacement for the microphone.

In one embodiment, the match identification unit is configured foroutputting one of a visual indication and an audio indication.

In one embodiment, the match identification unit is configured for:determining the match between the actual position and the targetposition for the given microphone if the actual position is comprisedwithin a range of position containing the target position; anddetermining the mismatch between the actual position and the targetposition for the given microphone if the actual position is outside ofthe range of position.

In one embodiment, the position determining unit is configured fordetermining the actual position of the microphone using a trilaterationmethod.

In one embodiment, the position determining unit is configured fordetermining the actual position of the microphone using a nonlinearleast squares fitting method.

According to still a further broad aspect, there is provided acomputer-implemented method for determining an actual position of amicrophone, comprising: sequentially emitting a first sound signal via afirst speaker positioned at a first speaker position, and a second soundsignal via a second speaker positioned at a second speaker position;measuring a first elapsed time between the emission of the first soundsignal by the first speaker and a detection of the first sound signal bythe microphone, and a second elapsed time between the emission of thesecond sound signal by the second speaker and a detection of the secondsound signal by the microphone; determining a first distance between thefirst speaker position and the microphone using the first elapsed time,and a second distance between the second speaker position and themicrophone using the second elapsed time and; determining the actualposition of the microphone using the first and second distances and thefirst and second speaker positions; and outputting the actual positionof the microphone.

In one embodiment, the method further comprises: emitting a third soundsignal via a third speaker positioned at a third speaker position;measuring a third elapsed time between the emission of the third soundsignal by the third speaker and a detection of the third sound signal bythe microphone; and determining a third distance between the thirdspeaker position and the microphone using the third elapsed time, saiddetermining the actual position of the microphone is performed usingfurther the third distance and the third speaker position.

In one embodiment, the method further comprises recording, via themicrophone, the first sound signal emitted by the first speaker, thesecond sound signal emitted by the second speaker and the third soundsignal emitted by the third speaker.

In one embodiment, an emission of the first sound signal and an emissionof the second sound signal are spaced apart by a first time delay and anemission of the second sound signal and an emission of the third soundsignal are spaced apart by a second time delay.

In one embodiment, the first and second time delays are each greaterthan a reverberation time.

In one embodiment, said determining the actual position of themicrophone is performed using a trilateration method.

In one embodiment, said determining an actual position of the microphoneis performed using a nonlinear least squares fitting method.

According to still another broad aspect, there is provided a system fordetermining an actual position of a microphone, comprising: acommunication unit for at least one of receiving and transmitting data,a memory and a processing unit configured for executing the steps of theabove method.

According to still a further broad aspect, there is provided system fordetermining an actual position of a microphone, comprising: a soundemitting unit configured for successively emitting a first sound signalvia a first speaker positioned at a first speaker position and a secondsound signal via a second speaker positioned at a second speakerposition; a distance measurement unit configured for: measuring a firstelapsed time between the emission of the first sound signal by the firstspeaker and a detection of the first sound signal by the microphone anda second elapsed time between the emission of the second sound signal bythe second speaker and a detection of the second sound signal by themicrophone; and determining a first distance between the first speakerposition and the microphone using the first elapsed time and a seconddistance between the second speaker position and the microphone usingthe second elapsed time; and a position determining unit configured fordetermining the actual position of the microphone using the first andsecond distances and the first and second speaker positions, andoutputting the actual position of the microphone.

In one embodiment, the sound emitting unit is further configured foremitting a third sound signal via a third speaker positioned at a thirdspeaker position; the distance measurement unit is further configuredfor: measuring a third elapsed time between the emission of the thirdsound signal by the third speaker and a detection of the third soundsignal by the microphone; and determining a third distance between thethird speaker position and the microphone using the third elapsed time;and the position determining unit is configured for determining theactual position of the microphone using further the third distance andthe third speaker position.

In one embodiment, the system further comprises a sound recording unitconnectable to the microphone and configured for recording, via themicrophone, the first sound signal emitted by the first speaker, thesecond sound signal emitted by the second speaker and the third soundsignal emitted by the third speaker.

In one embodiment, an emission of the first sound signal and an emissionof the second sound signal are spaced apart by a first time delay and anemission of the second sound signal and an emission of the third soundsignal are spaced apart by a second time delay.

In one embodiment, the first and second time delays are each greaterthan a reverberation time.

In one embodiment, the position determining unit is configured fordetermining the actual position of the microphone using a trilaterationmethod.

In one embodiment, the position determining unit is configured fordetermining the actual position of the microphone using a nonlinearleast squares fitting method.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will becomeapparent from the following detailed description, taken in combinationwith the appended drawings, in which:

FIG. 1 is a flow chart of a method for determining whether a microphoneoccupies a desired position using time delays between successivelydetected signals, in accordance with an embodiment;

FIG. 2 illustrates an exemplary positioning of a microphone relative tothree speakers, in accordance with an embodiment;

FIG. 3 illustrates the temporal emission of three sound signals by threedifferent speakers, in accordance with an embodiment;

FIG. 4 illustrates the detection of the three sound signals of FIG. 3,in accordance with an embodiment;

FIG. 5 is a block diagram of a system for determining whether amicrophone occupies a desired position using time delays betweensuccessively detected signals, in accordance with an embodiment;

FIG. 6 is a block diagram of a processing module adapted to execute atleast some of the steps of the method of FIG. 1, in accordance with anembodiment;

FIG. 7 is a flow chart of a method for determining whether a microphoneoccupies a desired position via the determination of an actual positionof the microphone, in accordance with an embodiment;

FIG. 8 is a block diagram of a system for determining whether amicrophone occupies a desired position via the determination of anactual position of the microphone, in accordance with an embodiment; and

FIG. 9 is a block diagram of a processing module adapted to execute atleast some of the steps of the method of FIG. 7, in accordance with anembodiment.

It will be noted that throughout the appended drawings, like featuresare identified by like reference numerals.

DETAILED DESCRIPTION

FIG. 1 illustrates one embodiment of a method 10 for determining whethera microphone is positioned at a target and desired position. The method10 is to be performed by a computer machine provided with at leastcommunication means, a processing unit and a memory. For example, themethod 10 may be used for calibrating sound and/or running sound testsin a simulator such as a vehicle simulator. In such cases, positioning amicrophone at the same position as a previous position is of importancefor ensuring that the calibration is correct and/or the results of thetests are reliable.

The method 10 is performed using at least two speakers connected to aplayback system for playing back sound signals via each one of thespeakers. Each speaker is located at a fixed position which does notvary in time. In one embodiment, the position of each speaker is unknownwhile being constant in time. In another embodiment, the position ofeach speaker is known and constant in time.

At step 12, a reference time delay is received. In order to obtain thetime reference time delay, a microphone is positioned at a givenposition 30 relative to two speakers 32 and 34. The given position 30 isreferred hereinafter to as the target position for the microphone sincethe aim the method 10 is to help a user position a microphone at theposition 30. The reference time delay corresponds to the time delay thatoccurs between the capture of a first reference sound signal and thecapture of a second reference sounds signal. The capture of the firstand second reference sound signals is performed by the a microphonewhile the microphone is positioned at the position 30.

The first reference sound signal is emitted by a first speaker, e.g.speaker 32, while the second reference sound signal is emitted by asecond and different speaker, e.g. speaker 34. The playback system usedfor playing back the first and second reference sound signals via thefirst and second speakers, respectively, is configured for successivelyplaying back the first and second reference sound signals so that a timedelay is present between the end of the playback of the first referencesound signal via the first speaker and the beginning of the playback ofthe second reference sound signal via the second speaker. This timedelay is referred to as the reference time delay hereinafter.

In an embodiment in the method 10 is performed in a closed space or apartially-closed space such as in a simulator, the reference time delayis chosen to be greater than the reverberation time of the closed orpartially-closed space. In another embodiment, the reference time delayis chosen to be equal to or less than the reverberation time of theclosed or partially-closed space.

Referring back to FIG. 1, a microphone is positioned at a given positionrelative to the first and second speakers in order to perform steps14-22 of the method 10. In one embodiment, the microphone is positionedat a random location relative to the first and second speakers. Inanother embodiment, the microphone is positioned at a position believedto be at least close to the target position. Using the playback system afirst test sound signal is emitted via the first speaker and recordedusing the microphone at the given position. Then a second test soundsignal is emitted via the second speaker and recorded by the microphoneat the given position. The playback system is configured for playingback the first and second test sound signals so that the first andsecond test signals are temporally spaced apart by the same time delayas the one between the first and second reference sound signals, i.e. bythe reference time delay.

FIG. 3 is an exemplary graph illustrating the successive emission of thefirst test sound signal 40 on the first channel 42, i.e. by the firstspeaker, and a second test sound signal 42 on a second channel, i.e. bythe second speaker. The first and second test sound signals are spacedapart by a time delay δt1, i.e. the time elapsed between the end of thefirst test sound signal and the beginning of the second test soundsignal 42.

The emitted sound signals are captured by the microphone and recorded,thereby obtaining a first recorded sound signal and a second recordedsound signal. At step 16, the actual time delay between the firstrecorded sound signal and the second recorded sound signal isdetermined.

FIG. 4 is an exemplary graph illustrating first and second sound signalsrecorded using the microphone at the given position. The first recordedsound signal 46 and the second recorded sound signal 48 are temporallyspaced apart by an actual time delay Δt1 which corresponds to the timedifference between the end of the first recorded sound signal 46 and thebeginning of the second recorded sound signal 48.

At step 18, the actual time delay is compared to the reference timedelay received at step 12. At step 20, it is determined whether there isa match between the given position of the microphone that was used torecording the test sound signals at step 14 and the target position forthe microphone using the result of the comparison performed at step 18.

If the actual time delay substantially correspond to the reference timedelay, then it is concluded that there is a match between the given oractual position of the microphone and the target position. On the otherend, if the actual time delay is different from the reference timedelay, then it is concluded that there is no match between the givenposition of the microphone and the target position, i.e. the microphoneis not located at the target position required for performing a soundtest for example.

In one embodiment, a match is determined when the actual time delay iscomprised within a predefined range of time delays which contains thereference time delay, and a mismatch is determined when the actual timedelay is outside of the range of time delays.

At step 22, an indication of the match/mismatch between the givenposition of the microphone and its target position is outputted. In oneembodiment, the indication of the match/mismatch is stored in memory.

In one embodiment, step 22 consists in outputting an indication onlywhen a match between the given position of the microphone and the targetposition is found.

In another embodiment, step 22 consists in outputting an indication onlywhen a mismatch is found between the given position of the microphoneand the target position.

In a further embodiment, two different types of indication may beoutputted at step 22. A first indication of a match may be outputtedwhen a match between the given position of the microphone and the targetposition is found, and a second and different indication may beoutputted when a mismatch between the given position of the microphoneand the target position is found.

In one embodiment, the indication of the match/mismatch is a visualindication. For example, a light may illuminate to indicate a matchbetween the given position of the microphone and the target position.

In another embodiment, the indication of the match/mismatch is an audioindication. For example, a sound may be emitted when a match between thegiven position of the microphone and the target position is found.

It should be understood that the position of the speakers is fixed anddoes not vary in time, i.e. the position of the speakers at the time ofemitting the test sound signals is identical to that the speakers at thetime of emitting the reference sound signals.

In one embodiment, the first and second test sound signals areidentical. In another embodiment, the first and second test soundsignals may be different. Similarly, the first and second referencesound signals may be identical. Alternatively, they may be different. Itshould also be understood that the first test sound signal may beidentical to the first reference sound signal and/or the second testsound signal may be identical to the second reference sound signal.Alternatively, the first test sound signal may be different from thefirst reference sound signal and/or the second test sound signal may bedifferent from the second reference sound signal.

In one embodiment, the same microphone is used for both generating thefirst and second reference signals and the first and second soundsignals recorded at step 14. In another embodiment, differentmicrophones may be used.

In one embodiment, the method 10 further comprises emitting the firsttest sound signal and emitting the second test sound signal.

In one embodiment, the method 10 further comprises receiving a secondreference time delay at step 12. In order to obtain the second referencetime delay, the microphone is positioned at the target position 30illustrated in FIG. 2. The second reference time delay corresponds tothe time delay that occurs between the capture of the second referencesound signal and the capture of a third reference sounds signal emittedby a third speaker, e.g. speaker 38.

As described above, the second reference sound signal is emitted by thesecond speaker, e.g. speaker 34, while the third reference sound signalis emitted by the third and different speaker, e.g. speaker 38. Theplayback system used for playing back the second and third referencesound signals via the second and third speakers, respectively, isconfigured for successively playing back the second and third referencesound signals so that a time delay is present between the end of theplayback of the second reference sound signal emitted via the secondspeaker and the beginning of the playback of the third reference soundsignal emitted via the third speaker. This second reference time delaymay be identical to the above-described first reference time delay.Alternatively, second reference time delay may be different from thefirst reference time delay.

When a second reference time delay is received at step 12, a third testsound signal is played back via the third speaker and recorded using themicrophone located at the given position. The emission of the third testsound signal is spaced apart from the second test signal by an amount oftime corresponding to the second reference time delay. Referring back toFIG. 3, a third test sound signal 50 is emitted on the third channel,i.e. via the third speaker. The second and third test sound signals arespaced apart by a time delay δt2, i.e. the time elapsed between the endof the second test sound signal and the beginning of the third testsound signal 42.

At step 14, the third test sound signal is captured and recorded at step14 using the microphone being positioned at the given position. A step16, a second actual time delay, i.e. the actual time delay between thesecond recorded sound signal and the third recorded sound signal, isdetermined.

Referring back to FIG. 4, the second recorded sound signal 48 and thesecond recorded sound signal 52 are temporally spaced apart by a secondactual time delay Δt2 which corresponds to the time difference betweenthe end of the second recorded sound signal 48 and the beginning of thethird recorded sound signal 52.

Step 18 further comprises comparing the second actual time delay to thesecond reference time delay received at step 12. At step 20, the matchor mismatch between the given position of the microphone and the targetposition is performed according to the result of the comparisonperformed at step 18.

In one embodiment, a match between the given position of the microphoneand the target position is determined only if the first actual timedelay between the captured first and second test sounds signalscorrespond to the first reference time delay and the second actual timedelay between the captured second and third test sounds signalscorrespond to the second reference time delay. As described above, arange of reference time delay values may be used for determining whethera match occurs.

In one embodiment, a mismatch between the given position of themicrophone and the target position is determined if the first actualtime delay between the captured first and second test sounds signals isdifferent from the first reference time delay and/or the second actualtime delay between the captured second and third test sounds signals isdifferent from the second reference time delay.

It should be understood that the method 10 may be embodied as a computermachine comprising at least one processing unit or processor, acommunication unit and a memory having stored thereon statements and/orinstructions that, when executed by the processing unit, executes thesteps of the method 10.

FIG. 5 illustrates one embodiment of a system 60 comprising at least asound recording unit 62, a time delay unit 64 and a match identificationunit 66.

The sound recording unit 62 is connectable to the microphone 68positioned at the given position and configured for recording, via themicrophone 68, the first and second test sound signals described above,and optionally the third test sound signal if any. The recorded testsound signals are then transmitted to the time delay unit 64.

The time delay unit 64 is configured for determining the actual timedelay between the first and second recorded test sound signals, andoptionally the second actual time delay between the second and thirdrecorded test sound signals, as described above with respect to themethod 10. The determined time delay(s) is(are) transmitted to the matchidentification unit 66.

The match identification unit 66 receives the reference time delay(s)and is configured for comparing the determined time delay(s) to thereference time delay(s) as described above, to determine if the given oractual position of the microphone corresponds to the target position andoutput an indication of the match/mismatch, as described above withrespect to the method 10.

In one embodiment, the system 60 further comprises a sound emitting unitconnected to the speakers and configured for playing back the test soundsignals via the speakers according to the reference time delay(s), asdescribed above with respect to the method 10.

In one embodiment, the system 60 further comprises a memory on which adatabase storing is stored. The database may contain the reference timedelay(s) and the test sound signals to be played back for example.

In one embodiment, the system 60 may further comprise a visualindicating device such as a lighting system, a display or the like forvisually informing the user of the match/mismatch. For example, thematch identification unit 66 may be configured to generate a writtenmessage indicative of the match/mismatch and transmit the generatedmessage to a display to be displayed thereon.

In another embodiment, the match identification unit 66 may be connectedto a given one of the speakers used for playing back the test soundsignals and configured for generating an audio signal to be played backvia the given speaker. Alternatively, a further speaker may be used forplaying back the audio signal.

In one embodiment, each one of the units 62-66 is provided with arespective processing unit such as a microprocessor, a respective memoryand respective communication means. In another embodiment, at least twoof the units 62-66 may share a same processing unit, a same memoryand/or same communication means. For example, the system 60 may comprisea single processing unit used by each unit 62-66, a single memory and asingle communication unit.

FIG. 6 is a block diagram illustrating an exemplary processing module 80for executing the steps 12 to 22 of the method 10, in accordance withsome embodiments. The processing module 80 typically includes one ormore Computer Processing Units (CPUs) and/or Graphic Processing Units(GPUs) 82 for executing modules or programs and/or instructions storedin memory 84 and thereby performing processing operations, memory 84,and one or more communication buses 86 for interconnecting thesecomponents. The communication buses 86 optionally include circuitry(sometimes called a chipset) that interconnects and controlscommunications between system components. The memory 84 includeshigh-speed random access memory, such as DRAM, SRAM, DDR RAM or otherrandom access solid state memory devices, and may include non-volatilememory, such as one or more magnetic disk storage devices, optical diskstorage devices, flash memory devices, or other non-volatile solid statestorage devices. The memory 84 optionally includes one or more storagedevices remotely located from the CPU(s) 82. The memory 84, oralternately the non-volatile memory device(s) within the memory 84,comprises a non-transitory computer readable storage medium. In someembodiments, the memory 84, or the computer readable storage medium ofthe memory 84 stores the following programs, modules, and datastructures, or a subset thereof:

a sound recording module 90 for generating recorded test sound signals;

a time delay module 92 for calculating the time delay between tworecorded test sound signals;

a match identification module 94 for determining a match/mismatchbetween the actual position of the microphone and its target position;and

a sound emitting module 96 for playing back the test sound signals viathe speakers.

It should be understood that the distance module 96 may be omitted.

Each of the above identified elements may be stored in one or more ofthe previously mentioned memory devices, and corresponds to a set ofinstructions for performing a function described above. The aboveidentified modules or programs (i.e., sets of instructions) need not beimplemented as separate software programs, procedures or modules, andthus various subsets of these modules may be combined or otherwisere-arranged in various embodiments. In some embodiments, the memory 84may store a subset of the modules and data structures identified above.Furthermore, the memory 84 may store additional modules and datastructures not described above.

Although it shows a processing module 80, FIG. 6 is intended more asfunctional description of the various features which may be present in amanagement module than as a structural schematic of the embodimentsdescribed herein. In practice, and as recognized by those of ordinaryskill in the art, items shown separately could be combined and someitems could be separated.

FIG. 7 illustrates one embodiment of a further method 100 fordetermining whether a given microphone is positioned at a desiredposition.

Similarly to the method 10, the method 100 may be used in the context ofa simulator such as a vehicle simulator in order to ensure that amicrophone to be used in a sound text for example is positioned at adesired position.

The microphone is positioned at given position and the method 100 isperformed in order to determine whether the given position at which themicrophone is corresponds or not the desired position for themicrophone.

At step 102, the target or desired position for the microphone isreceived. The position of the three speakers to be used for emittingsound signals is also received at step 102. A position may be expressedas coordinates (x, y, z) for example.

At step 105, three sound signals are emitted sequentially each from arespective speaker. Referring back to FIG. 2, a first sound signal isemitted via the first speaker 32, a second sound signal is emitted viathe second speaker 34 and a third sound signal is emitted via the thirdspeaker 38.

In one embodiment, a time delay exists between the end of the emissionof a sound signal and the beginning of the emission of the subsequentsound signal. For example, a first reference time delay is presentbetween the end of the emission of the first sound signal by the firstspeaker 32 and the beginning of the emission of the second sound signalby the second speaker 34, and a second time delay is present between theend of the emission of the second sound signal and the beginning of theemission of the third sound signal by the third speaker 38.

In one embodiment, the first and second time delays are identical. Inanother embodiment, the first and second time delays are different.

In one embodiment, the first and/or second time delays are chosen so tobe longer than the reverberation time of the room in which the method100 is performed to avoid or limit interferences between echoes of agiven sound signal and a subsequent sound signal.

At step 106, the sound signal emitted at step 104 are detected by themicrophone and the propagation time between the respective speaker thatemitted the sound signal and the microphone is determined for each oneof the three signals. The propagation time corresponds to the timeelapsed between the beginning of the emission of a sound signal via itsspeaker and the beginning of the reception of the same sound signal bythe microphone. The person skilled in the art will understand that thepropagation time may also be defined as the time elapsed between the endof the emission of a sound signal by a speaker and the end of thereception of the same sound signal by the microphone.

As a result, a first propagation time is determined for the first soundsignal emitted by the first speaker, a second propagation time isdetermined for the second sound signal emitted by the second speaker anda third propagation time is determined for the third sound signalemitted by the third speaker.

At step 108, for each emitted sound signal, the distance between therespective speaker that emitted the sound signal and the microphone isdetermined using the respective propagation time determined at step 106and the speed of sound. As a result, the distance between the firstspeaker and the microphone is determined using the propagation timedetermined for the first sound signal, the distance between the secondspeaker and the microphone is determined using the propagation timedetermined for the second sound signal and the distance between thethird speaker and the microphone is determined using the propagationtime determined for the third sound signal.

At step 110, the actual position of the microphone from which the threesound signals have been detected is determined using the determineddistances between the microphone and the three speakers used foremitting the three sound signals, as described above.

Then the actual position of the microphone determined at step 110 iscompared to the target position for the microphone received at step 102.At step 114, it is determined whether the actual position of themicrophone matches the target position. If the determined actualposition corresponds to the target position, then a match between theactual position of the microphone and the target position is determined.On the other end, if the determined actual position of the microphone isdifferent from the target position for the microphone, then a mismatchbetween the actual position and the target position is determined. Theindication of the match/mismatch between the actual position of themicrophone and its target position is outputted at step 116. In oneembodiment, the indication of the match/mismatch is stored in memory.

In one embodiment, step 116 consists in outputting an indication onlywhen a match between the actual position of the microphone and thetarget position is found.

In another embodiment, step 116 consists in outputting an indicationonly when a mismatch is found between the actual position of themicrophone and the target position.

In a further embodiment, two different types of indication may beoutputted at step 116. A first indication of a match may be outputtedwhen a match between the actual position of the microphone and thetarget position is found, and a second and different indication may beoutputted when a mismatch between the actual position of the microphoneand the target position is determined.

In one embodiment, the indication of the match/mismatch is a visualindication. For example, a light may be illuminated to indicate a matchbetween the actual position of the microphone and the target position.

In another embodiment, the indication of the match/mismatch is an audioindication. For example, a sound may be emitted when a match between theactual position of the microphone and the target position is found.

In one embodiment, the method 100 further comprises a step ofcalculating the position difference between target position and actualposition such as the vector from the actual position to the targetposition. In this case, the method 100 may further comprise a step ofdetermining instructions for moving the microphone from the actualposition to the target position based on the position difference andoutputting the instructions. In one embodiment, the instructions may bedisplayed on a display. In another embodiment, the instructions may beverbal instructions.

It should be understood that the position of the three speakers is fixedand does not vary in time, i.e. the position of the speakers at the timeof emitting the test sound signals is identical to that the speakers atthe time of emitting the reference sound signals and the position at thetime of determining the target position of the microphone is identicalto that at the time of executing the method 100.

In one embodiment, the three sound signals emitted at step 104 areidentical. In another embodiment, at least one of the three soundsignals is different from the other two sound signals.

In one embodiment, the target position corresponds to a previousposition for the microphone that was used for calibrating the soundsystem of a simulator or performing a sound test for example. In thiscase, the target position may have been determined using steps 104-110of the method 100.

In one embodiment, the determination of the actual microphone positionusing a trilateration method, as known in the art. In this case, knowingthe distance between each speaker and the microphone, the position ofthe microphone relative to that of the three speakers is determinedusing the geometry of circles, spheres or triangles, as known in theart.

In another embodiment, the determination of the actual microphoneposition is determined using a nonlinear least square fitting method, asknown in the art. In this case, the actual position of the microphone isiteratively determined and may be expressed as follows:

$P_{Next} = {{\frac{1}{N}{\sum\limits_{i = 0}^{N}S_{i}}} + {D_{i}*\frac{P_{Prev} - S_{i}}{{P_{Prev} - S_{i}}}}}$

where P_(Next), P_(Prev), D_(i) et S_(i) are position vectors expressedin the coordinate system (x,y,z);

P_(Next) is the next position for the microphone;

P_(Prev) is the previous determined position for the microphone;

N is the number of speakers (N=3 in the present case);

D_(i) is the distance between the microphone and the speaker i; and

S_(i) is the position of the speaker i;

In one embodiment, the first previous position, i.e. P₀, used in themethod corresponds to the position that was determined the last time themethod was executed. In another embodiment, P₀ is chosen as being theaverage position of the speakers positions. In a further embodiment, thefirst previous position P₀ is chosen as being the center of the triangleformed by the three speakers.

It should be understood that the method 100 may be embodied as acomputer machine comprising at least one processing unit or processor, acommunication unit and a memory having stored thereon statements and/orinstructions that, when executed by the processing unit, executes thesteps of the method 100.

In one embodiment, only steps 104 to 110 of the method 100 may beperformed to determine the actual position of the microphone. Theresulting method is then a method is then a computer-implemented methodfor determining the actual position of a microphone.

While the above method 100 and system 140 each refer to the emission ofthree sound signals by three separate speakers, the person skilled inthe art will understand that only two sound signals may be sequentiallyemitted by two distinct speakers each having a respective position. Inthis case, the step 106 comprises measuring a first elapsed time betweenthe emission of the first sound signal by the first speaker and adetection of the first sound signal by the microphone, and a secondelapsed time between the emission of the second sound signal by thesecond speaker and a detection of the second sound signal by themicrophone. The step 108 then comprises determining a first distancebetween the first speaker position and the microphone using the firstelapsed time, and a second distance between the second speaker positionand the microphone using the second elapsed time. It should also beunderstood that the step 110 of determining the actual position of themicrophone is performed using only using the first and second determineddistances and the positions of the first and second speakers.

When only two speakers are used, the actual position of the microphonemay be determined by choosing a point located on the circle representingthe intersection of a first sphere having its center located at theposition of the first speaker and its radius corresponding to thedetermined distance between the microphone and the first speaker, and asecond sphere having its center located at the position of the secondspeaker and its radius corresponding to the determined distance betweenthe microphone and the second speaker. The actual point of themicrophone is then chosen as being the point of the intersection circlethat is the closest to a reference point. The reference point may be theaverage position between the positions of the two speakers. In anotherexample, the actual position of the microphone may be a point randomlychosen on the circle.

FIG. 8 illustrates one embodiment of a system 140 for determiningwhether a given microphone is positioned at a desired or targetposition. The system comprises a sound emitting unit 142, a soundrecording unit 144, a distance measurement unit 146, a positiondetermining unit 148 and a match identification unit 150.

The sound emitting unit 142 is connected to the three speakers 152 andconfigured for generating three sound signals and playing back the threesound signals via three different speakers each having a respectivefixed and known position. In one embodiment, the three sound signals tobe played back by each speaker 152 are stored into a database and thesound emitting unit 142 is configured for retrieving the sound signal tobe played back by each speaker 152 and playing back the sound signalsvia their respective speaker 152, two successive sound signals beingtemporally spaced apart by a respective time delay, as described abovewith respect to the method 100.

The sound recording unit 144 is connected to the microphone positionedat an actual or given position and is configured for recording the soundsignals captured by the microphone and emitted by the speakers 154, asdescribed above with respect to the method 100.

The distance measurement unit 146 receives the determined distancebetween the microphone and each speaker 152 from the sound recordingunit 144 and is configured for determining the propagation time of eachsignal and determining the actual distance between the microphone 154and each speaker 152 using the speed of sound and the respectivepropagation time, as described above with respect to the method 100.

The position determining unit 148 receives the positions of the threespeakers which may be stored in the database for example and thedistance between the microphone and each speaker and is configured fordetermining the actual position of the microphone as described abovewith respect to the method 100.

The match identification unit 150 receives the target position for themicrophone which may be stored in the database for example and theactual position of the microphone and is configured for determining amatch/mismatch between the actual position of the microphone and itstarget position, as described above with respect to the method 100.

In one embodiment, the system 140 may further comprise a visualindicating device such as a lighting system, a display or the like forvisually informing the user of the match/mismatch. For example, thematch identification unit 150 may be configured to generate a writtenmessage indicative of the match/mismatch and transmit the generatedmessage to a display to be displayed thereon.

In another embodiment, the match identification unit 150 may beconnected to a given one of the speakers used for playing back the testsound signals and configured for generating an audio signal to be playedback via the given speaker. Alternatively, a further speaker may be usedfor playing back the audio signal.

In one embodiment, the match identification unit 150 is furtherconfigured for determining a difference between the actual position andthe target position and generate instructions for moving the microphoneform the actual position to the target position, as described above.

In one embodiment, each one of the units 142-150 is provided with arespective processing unit such as a microprocessor, a respective memoryand respective communication means. In another embodiment, at least twoof the units 62-66 may share a same processing unit, a same memoryand/or same communication means. For example, the system 140 maycomprise a single processing unit used by each unit 142-150, a singlememory and a single communication unit.

In one embodiment, the match identification unit 150 may be omitted. Inthis case, the resulting system is a system for determining the actualposition of a microphone.

FIG. 9 is a block diagram illustrating an exemplary processing module160 for executing the steps 102 to 116 of the method 100, in accordancewith some embodiments. The processing module 160 typically includes oneor more Computer Processing Units (CPUs) and/or Graphic Processing Units(GPUs) 162 for executing modules or programs and/or instructions storedin memory 164 and thereby performing processing operations, memory 164,and one or more communication buses 166 for interconnecting thesecomponents. The communication buses 166 optionally include circuitry(sometimes called a chipset) that interconnects and controlscommunications between system components. The memory 164 includeshigh-speed random access memory, such as DRAM, SRAM, DDR RAM or otherrandom access solid state memory devices, and may include non-volatilememory, such as one or more magnetic disk storage devices, optical diskstorage devices, flash memory devices, or other non-volatile solid statestorage devices. The memory 164 optionally includes one or more storagedevices remotely located from the CPU(s) 162. The memory 164, oralternately the non-volatile memory device(s) within the memory 164,comprises a non-transitory computer readable storage medium. In someembodiments, the memory 164, or the computer readable storage medium ofthe memory 164 stores the following programs, modules, and datastructures, or a subset thereof:

a sound emitting module 170 for emitting sound signals via speakers;

a time measurement module 172 for measuring the propagation time of eachemitted sound signal

a distance measurement module 174 determining the distance between themicrophone and each speaker;

a position determining module 176 for determining the actual position ofthe microphone;

a match identification module 178 for determining a match/mismatchbetween the actual position of the microphone and its target positionand

a sound recording module 180 for recording the sound signals captured bythe microphone.

It should be understood that the sound recording module 180 may beomitted.

Similarly, the match identification module 178 may be omitted. In thiscase, the processing module 160 is configured for only determining theactual position of a microphone.

Each of the above identified elements may be stored in one or more ofthe previously mentioned memory devices, and corresponds to a set ofinstructions for performing a function described above. The aboveidentified modules or programs (i.e., sets of instructions) need not beimplemented as separate software programs, procedures or modules, andthus various subsets of these modules may be combined or otherwisere-arranged in various embodiments. In some embodiments, the memory 164may store a subset of the modules and data structures identified above.Furthermore, the memory 164 may store additional modules and datastructures not described above.

Although it shows a processing module 160, FIG. 9 is intended more asfunctional description of the various features which may be present in amanagement module than as a structural schematic of the embodimentsdescribed herein. In practice, and as recognized by those of ordinaryskill in the art, items shown separately could be combined and someitems could be separated.

While the above methods and systems are described in the context of avehicle simulator such as an aircraft simulator, it should be understoodthat the methods and systems may be used in other contexts in which amicrophone has to be positioned at a target position at which themicrophone has to be positioned such as a previous position at which themicrophone was positioned. The above-described methods and systems maybe used for determining whether the actual position of the microphonecorresponds or not o the target position.

The embodiments of the invention described above are intended to beexemplary only. The scope of the invention is therefore intended to belimited solely by the scope of the appended claims.

I claim:
 1. A computer-implemented method for determining whether agiven microphone occupies a target position, comprising: receiving areference time delay between a first reference signal emitted by a firstspeaker and recorded by a reference microphone having the targetposition and a second reference signal emitted by a second speaker andrecorded by the reference microphone having the target position, thefirst and second speakers each having a fixed position, the emission ofthe first and second reference signals being spaced apart by a referencetime delay and the reference time delay being chosen to be greater thana reverberation time; using the given microphone positioned at a givenposition, recording a first sound signal emitted by the first speakerand a second sound signal emitted by the second speaker, the emission ofthe first and second sound signals being spaced apart by the referencetime delay; determining an actual time delay between the first soundsignal and the second sound signal; comparing the actual time delay tothe reference time delay; determining a match between the given positionand the target position for the given microphone if the actual timedelay corresponds to the reference time delay and a mismatch between thegiven position and the target position for the given microphone if theactual time delay is different from the reference time delay; andoutputting an indication of one of the match and the mismatch.
 2. Thecomputer-implemented method of claim 1, wherein said outputting anindication comprises outputting an indication of the match between thegiven position and the target position for the given microphone.
 3. Thecomputer-implemented method of claim 1, wherein said outputting anindication comprises outputting an indication of the mismatch betweenthe given position and the target position for the given microphone, theindication of the mismatch comprising at least one of a suggesteddisplacement for displacing the given microphone, a visual indicationand an audio indication.
 4. The computer-implemented method of claim 1,further comprising: emitting the first sound signal via the firstspeaker; and emitting the second sound signal via the second speakerafter the reference time delay.
 5. The computer-implemented method ofclaim 1, wherein said determining the match comprises determining thematch between the given position and the target position for the givenmicrophone if the actual time delay is comprised within a range of timedelay containing the reference time delay and said determining themismatch comprises determining the mismatch between the given positionand the target position for the given microphone if the actual timedelay is outside of the range of time delay.
 6. The computer-implementedmethod of claim 1, further comprising: receiving a further referencedelay between the second reference signal and a third reference signalemitted by a third speaker and recorded by the microphone having thetarget position, the third speaker having a fixed location and theemission of the second and third reference signals being spaced apart bya predefined time delay; recording, via the given microphone positionedat the given position, a third sound signal emitted by the thirdspeaker, the emission of the second and third sound signals being spacedapart by the predefined time delay; determining a given time delaybetween the second sound signal and the third sound signal; andcomparing the given time delay to the further reference delay; saiddetermining the match comprising determining the match between the givenposition and the target position for the given microphone if the actualtime delay corresponds to the reference time delay and the given timedelay corresponds to the further reference delay, and said determiningthe mismatch comprising determining the mismatch between the givenposition and the target position for the given microphone if at leastone of the actual time delay is different from the reference time delayand the given time delay is different from the further reference delay.7. The computer-implemented method of claim 6, wherein the predefinedtime delay is chosen to be greater than a reverberation time.
 8. Thecomputer-implemented method of claim 6, wherein said determining thematch comprises determining the match between the given position and thetarget position for the given microphone if the actual time delay iscomprised within a first range of time delay containing the referencetime delay and the given time delay is comprised within a second rangeof time delay containing the further reference delay, and saiddetermining the mismatch comprises determining the mismatch between thegiven position and the target position for the given microphone if atleast one of the actual time delay is outside the first range of timedelay and the given time delay is outside the second range of timedelay.
 9. The computer-implemented method of claim 1, wherein thereference microphone corresponds to the given microphone.
 10. A systemfor determining whether a given microphone occupies a target position,comprising: a sound recording unit connectable to the given microphoneto be positioned at a given position, the sound recording unitconfigured for recording a first sound signal emitted by a first speakerand a second sound signal emitted by a second speaker, the emission ofthe first and second sound signals being spaced apart by a referencetime delay, the first and second speakers each having a fixed positionand the reference time delay being chosen to be greater than areverberation time; a time delay unit configured for determining anactual time delay between the first sound signal and the second soundsignal; a match identification unit configured for: receiving areference time delay between a first reference signal emitted by thefirst speaker and recorded by a reference microphone having a targetposition and a second reference signal emitted by the second speaker andrecorded by the reference microphone having the reference position, theemission of the first and second reference signals being spaced apart bythe reference time delay; comparing the actual time delay to thereference time delay; determining a match between the given position andthe reference position for the given microphone if the actual time delaycorresponds to the reference time delay and a mismatch between the givenposition and the target position for the given microphone if the actualtime delay is different from the reference time delay; and outputting anindication of one of the match and the mismatch.
 11. The system of claim10, wherein the match identification unit is configured for outputtingthe indication of the match between the given position and the targetposition for the given microphone.
 12. The system of claim 10, whereinthe match identification unit is configured for outputting theindication of the mismatch between the given position and the targetposition for the given microphone, the indication of the mismatchcomprising at least one of a suggested displacement for displacing thegiven microphone, a visual indication and an audio indication.
 13. Thesystem of any claim 10, further comprising a sound emitting unitconfigured for: emitting the first sound signal via the first speaker;and emitting the second sound signal via the second speaker after thereference time delay.
 14. The system of claim 10, wherein the matchidentification unit is configured for: determining the match between thegiven position and the target position for the given microphone if theactual time delay is comprised within a range of time delay containingthe reference time delay; and determining the mismatch between the givenposition and the target position for the given microphone if the actualtime delay is outside of the range of time delay.
 15. The system ofclaim 10, wherein: the sound recording unit is further configured forrecording, via the given microphone positioned at the given position, athird sound signal emitted by a third speaker, the emission of thesecond and third sound signals being spaced apart by a predefined timedelay; the time delay unit is further configured for determining a giventime delay between the second sound signal and the third sound signal;and the match identification unit is further configured for: receiving afurther reference delay between the second reference signal and a thirdreference signal emitted by the third speaker and recorded by themicrophone having the target position, the third speaker having a fixedlocation and the emission of the second and third reference signalsbeing spaced apart by the predefined time delay; comparing the giventime delay to the further reference delay; determining the match betweenthe given position and the reference position for the given microphoneif the actual time delay corresponds to the reference time delay and thegiven time delay corresponds to the further reference delay, anddetermining the mismatch between the given position and the referenceposition for the given microphone if at least one of the actual timedelay is different from the reference time delay and the given timedelay is different from the further reference delay.
 16. The system ofclaim 15, wherein the predefined time delay is chosen to be greater thana reverberation time.
 17. The system of claim 15, wherein the matchidentification unit is configured for: determining the match between thegiven position and the target position for the given microphone if theactual time delay is comprised within a first range of time delaycontaining the reference time delay and the given time delay iscomprised within a second range of time delay containing the furtherreference delay; and determining the mismatch between the given positionand the target position for the given microphone if at least one of theactual time delay is outside the first range of time delay and the giventime delay is outside the second range of time delay.
 18. The system ofclaim 10, wherein the reference microphone corresponds to the givenmicrophone.